1. Field of the Invention
The invention relates generally to modulators and more specifically to those for Class C, RF pulse amplifiers using transistor amplifier stages with "FAIL-SOFT".
2. Description of the Prior Art
Pulse modulation of transistor RF power stages is known to present various problems. One such problem is that of modulation linearity i.e., the modulated stage's ability to accurately reproduce the shape of video modulation signal on the envelope of an RF signal. Another problem is the spectrum generated as a result of modulation, specifically the problem of maintaining within the system prescribed limits. Both aforementioned problems are often complicated by the RF carrier frequency, the instantaneous bandwidth, temperature and the high magnitude currents involved, particularly where power levels are relatively high. In such applications as DME and TACAN equipment, pulse shape and spectrum occupied at RF are of critical importance.
This manner in which the invention deals with the aforementioned problems will be seen as this description proceeds.